Unit 3

Question 1

where is both arterial and venous drainage in the head

Answer 1

• the maxillary artery or vein

Question 2

what are the 3 divisions of the trigeminal nerve

Answer 2

1. V1: ophthalmic
2. V2: maxillary
3. V3: mandibular

Question 3

which of the 3 divisions of the trigeminal nerve is the only one to have both sensory and motor abilities

Answer 3

• mandibular nerve (V3)

Question 4

what muscles does the mandibular nerve innervate

Answer 4

• the muscles of mastication:
• masseter
• lateral pterygoid
• temporalis
• medial pterygoid
• also, interior digastric and mylohyoid

Question 5

what does the ophthalmic nerve exit from and what does it innervate

Answer 5

• exit: superior orbital fissure

- innervates: eye

Question 6

what does the maxillary nerve exit from

Answer 6

• exit: foramen rotundum

Question 7

after exiting the cranium, where does the maxillary cross and what 3 branches become of this

Answer 7

• crosses the pterygopalatine fossa, and branches into
  1. zygomatic nerve
  2. PSA nerve
  3. pterygopalatine nerves

Question 8

where does the maxillary nerve re-enter through

Answer 8

• the inferior orbital fissure occupying the infraorbital groove where it becomes the infraorbital nerve, then moves on infraorbital canal

Question 9

what 2 branches does the maxillary nerve break off into in the infraorbital canal

Answer 9

• MSA nerve
• ASA nerve
• • innervates all mx teeth, bone, periodontal structures

Question 10

what are dental plexuses

Answer 10

• networks of nerves crossing over each other

Question 11

how are individual teeth innervated

Answer 11

• from the terminal branches of larger nerves (called infiltration)

Question 12

what 4 areas do the pterygopalatine nerves supply

Answer 12

1. orbit
2. nose (nasopalatine nerve - branch)
3. palate (greater palatine nerve - branch)
4. pharynx

Question 13

where does the nasopalatine nerve travel and what does it innervate

Answer 13

• passes across the roof of the nasal cavity downwards and forwards in mucous membranes and nasal septum
• continues downward and enters the incisive canal, passes into oral cavity through the incisive foramen
• innervates the entire premaxilla (3-3)

Question 14

where does the greater palatine nerve travel and what does it innervate

Answer 14

• descends through the pterygopalatine canal and emerges on the hard palate through the greater palatine foramen
• innervates palatal soft tissue and bone distal to canine and extending to the midline and the soft palatine

Question 15

where does the mandibular nerve exit the cranium

Answer 15

• foramen ovale

Question 16

what are the motor and sensory functions of the anterior division of the mandibular nerve

Answer 16

• motor: muscles of mastication

- sensory: mucous membranes of cheek and buccal mucous membranes of mandibular molars

Question 17

where does the long buccal nerve travel

Answer 17

• crosses in front of the anterior border of ramus at the occlusal plane of mandibular 3rd or 2nd molar level, enters cheek through the buccinator muscle

Question 18

what does the long buccal nerve innervate

Answer 18

• buccal gingiva of the mandibular molars and the mucobuccal fold
• important in dental therapy requiring soft tissue manipulation (ie scaling)

Question 19

what is the function of the posterior division of the mandibular nerve

Answer 19

• mainly sensory (some motor)

Question 20

what is the function of the lingual nerve

Answer 20

• anterior and medial to IAN
• more superficial than IAN
• provides sensation and taste to tongue and mucous membranes of floor of the mouth and lingual gingiva

Question 21

what is the function of the inferior alveolar nerve

Answer 21

• largest branch of V3
• enters mandibular canal are mandibular foramen
• accompanied by IA artery and vein

Question 22

what 3 divisions does the inferior alveolar nerve divide into at the mental foramen

Answer 22

1. dental plexus
2. incisive nerve
3. mental nerve

Question 23

what does the IAN anesthetize

Answer 23

• pulp of the mandibular teeth to midline (quadrant), buccal gingiva of premolars and incisors to midline

Question 24

what 3 injections could we give to anesthetize an entire mandibular quadrant

Answer 24

• IAN + Li + LB

Question 25

what is the mylohyoid nerve

Answer 25

• motor and sensory

- may provide sensory innervation to the mandibular incisors as well as the mesial root of the mn first molar

Question 26

what is the significance of proper needle placement during anesthetic administration (5 points)

Answer 26

1. solution must be deposited within 8-10 mm of the nerve to block nerve impulse
2. clinician must be accurate with landmarks and depth of needle penetration
3. clinician must avoid touching the nerve as damage to the nerve can occur
4. clinician must be aware of blood vessels and must ALWAYS aspirate with syringe prior to administering anesthetic. if positive aspiration occurs, re-injection will be necessary. directly injecting into bloodstream is EXTREMELY dangerous
5. there will always be a chance of hematoma in highly vascularized areas (ie. PSA because venous plexus in the pterygomaxillary fossa… pterygoid plexus or veins)

Question 27

what can cause a hematoma

Answer 27

• the outpouring of blood into extravascular spaces can result from accidentally nicking a blood vessel during the injection of anesthetics (bruise)
• hematoma will rapidly increase in size until tx is instituted
• PSA most common, then mental/incisive and IAN